The invention relates to a sampler for melts, especially for slag lying on a molten metal, having a one piece or multi-piece body arranged on a carrier. The body has an intake and a sample chamber.
Such samplers are known, for example, from published patent applications JP 61-271452 or DE 197 52 743 A1. These slag samplers use the relatively lower density of slag relative to steel or iron melts in order to obtain neat samples. When the slag rises through the intake into the sample chamber, it can lead to an adherence of the slag on the sample chamber walls, with the consequence that the intake of slag into the sample chamber is disturbed or, in extreme cases, even prevented.
Proceeding from this prior art, an objective underlying the present invention is to improve the known samplers and make possible a high-grade sampling. The objective is accomplished for a sampler of the type described above wherein the intake has a surface which is formed at least partially by a slag-repellant material
With the slag-repellant material of the surface of the intake, an adherence of the slag in the intake and, in an extreme case, a blocking of the intake with slag is prevented. Surfaces which have carbon or graphite are especially satisfactory, wherein the graphite or the carbon is preferably uniformly distributed over the entire surface.
It is expedient to form the surface as a graphite layer or to construct it of cardboard or paper. Other materials, such as oil or slaked lime, can also be satisfactory. It is further advantageous to apply an (optionally additional) coating of Teflon(copyright) (polytetrafluoroethylene) to the surface. In particular, the part of the body having the intake can be constructed wholly or partially of the slag-repellant material.
In an advantageous embodiment of the invention, the intake is constructed cone-shaped, wherein the end with the smaller cross section is arranged on the sample chamber. Preferably the intake is arranged at least partially beneath the sample chamber in the immersion direction. In an advantageous embodiment of the invention, the sample chamber is constructed cylindrically, and the base surface of the sample chamber has an approximately circular cross section, whose diameter is greater than the thickness (height) of the sample chamber. The intake advantageously opens approximately centrally into the base surface of the sample chamber, which preferably has an annular lateral metal wall. In particular, the sample chamber can have metal walls on all sides.
It is advantageous herein that the opening in the sample chamber or in the metal wall of the sample chamber, through which the slag runs into the sample chamber, have the same size and shape as the end of the conical intake, so that a discontinuity at the opening of the sample chamber is avoided. The opening/mouth of the intake into the sample chamber preferably has a diameter of about 3 to 7 mm, in particular about 5 mm, in order to ensure an optimal intake of the slag into the sample chamber, and in order to prevent slag from flowing out of the sample chamber when raising the sampler after the sampling. It can be advantageous to construct the annular lateral wall thinner than the metal wall of the base surface of the sample chamber.
It has proven to be expedient that the annular lateral metal wall have recesses on its end face directed away from the mouth of the intake. These recesses can be formed in various shapes, for example saw toothed, triangular or rounded off. They make possible a gas passage, that is a gas venting from the sample chamber, in order to make room for the in-flowing molten metal. The lateral metal wall lies against a base surface of the sample chamber such that the gases can escape from the sample chamber through the recesses between the base surface and the lateral metal wall. For this purpose, it is advantageous that the recesses are distributed uniformly over the end face.
On the end face of the lateral metal wall facing away from the opening of the intake into the sample chamber, a cover can lie arranged as an appropriate base surface of the sample chamber, which is advantageously constructed of metal. It is of particular advantage for the cover to have an annular edge bent toward the lateral metal wall and which lies on the lateral metal wall. The cover thereby forms a sort of hollow space, so that the sample forming in the sample chamber projects beyond the end face of the lateral metal wall after removal from the sampler. This wall can then be used as an analysis surface, since it is also formed by the base surface or the cover. The lack of such a projection can lead to this analysis surface receding into the interior of the sample chamber, for example due to shrinkage, so that a measuring head of a measuring device or analysis device does not lie on the sample itself, but rather on the lateral metal wall, so that a correct measurement cannot be performed. The edge preferably projects about 0.5 to 2 mm from the main cover surface.
For ease of sampling, it is advantageous for the body to have an annular notch or groove on its exterior, which preferably tapers to a point at its bottom. A sort of predetermined breaking point is thereby created, at which the body can be destroyed following sampling, so that an easy sample removal is possible. For this purpose, it is particularly expedient that the notch is arranged running around the sample chamber or around the intake, in particular running around the mouth of the intake into the sample chamber.